Silicone compositions are used in a variety of protective coating applications. Such silicone compositions are particularly useful as coatings where the coated substrate is exposed to high temperatures. For example, boiler stacks, wood stoves, flues, and the like are heated substrates which would quickly degrade ordinary acrylic or epoxy based coatings. However, the high temperature stability of silicone polymers make these materials ideal for application in these high temperature situations.
Generally silicone coating compositions are produced from silicone resins which are highly branched and crosslinked silicone polymers. To these silicone resins, polydiorganosilicone fluids are added to modify certain properties of the resin. Polydiorganosiloxane fluids are substantially linear silicone polymers having functional groups which will react with the silicone resin.
Although silicone coatings are chemically stable at high temperature, full advantage of longer lifetime due to this chemical stability often cannot be taken because the coating fails physically under thermal shock conditions. For example, a silicone coating on a boiler stack at 800.degree. F. which would otherwise be expected to have a 5 year service life will peel and fail as a result of thermal shock from a rain storm.
Thus, it is an object of the present invention to produce thermal shock resistant silicone coatings compositions.
It is another object of the present invention to produce objects coated with thermal shock resistant silicone coating compositions.
It is still another object of the present invention to produce silicone based paints which are resistant to thermal shock failure.